Polyimide polymers having 12-F fluorine-containing linking groups

Abstract

The present invention provides novel heat stable polyimide and polyamic acid precursor polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more aromatic dianhydride monomers, at least one of said diamine monomers having the structure: ##STR1## wherein R is CF 3 or phenyl. The polyimides of this invention exhibit improved solubility and low temperature flow characteristics, low moisture uptake, high thermal stability, low dielectric constant and good hydrolytic stability.

What is claimed is: 
     
       1. A polyimide polymer or copolymer containing at least one structural unit of the formula: ##STR6## wherein R is selected from the group consisting of CF 3  and phenyl and A is a tetravalent aromatic organic radical wherein each pair of carbonyl groups are attached to adjacent carton atoms in the ring of moiety A, said polyimide having a weight average molecular weight of at least about 5,000. 
     
     
       2. The polymer of claim 1 wherein A is selected from the group consisting of phenylene, naphthalene, a bis-phenylene compound and mixtures thereof, which may be unsubstituted or ring substituted with a radical selected from the group consisting of halogen, hydroxy, C 1  to C 6  alkyl and C 1  to C 6  alkoxy. 
     
     
       3. The polymer of claim 3 prepared by forming the amide-acid condensation product of 4,4-bis[2-(aminophenyl) hexafluorisopropyl] diphenyl ether diphenyl ether with one or more aromatic dianhydrides and imidizing said amide-acid condensation product. 
     
     
       4. The polymer of claim 3 wherein said aromatic dianhydride is selected from the group consisting of bis (3,4-dicarboxyphenyl) ether dianhydride, 3,3'4,4'benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl tetracarboxylic acid dianhydride, 2,2-bis (3,4 dicarboxy phenyl) hexafluoropropane dianhydride, 1,2,4,5-benzene tetracarboxylic acid dianhydrie, 4,4'-bis diphenyl ether dianhydride, and mixtures thereof. 
     
     
       5. A polyimide polymer containing structural units of the formula: 
     
     
       6. The polymer of claim 1 wherein R is CF 3 . ##STR7## wherein R is selected from the group consisting of CF 3  and phenyl, A is a tetravalent aromatic organic radical wherein each pair of carbonyl groups are attached to adjacent carbon atoms in the ring moiety A, and n is a number sufficient to give rise to a polymer having an inherent viscosity of at least about 0.05 as measured from a solution of the polymer in dimethyl acetamide at 25° C. 
     
     
       7. The polymer of claim 6 wherein said aromatic dianhydride is selected from the group consisting of bis (3,4-dicarboxyphenyl) ether dianhydride, 3,3'4,4'benzophenone tetracarboxylic dianhydride, 
     
     
       8. The polymer of claim 5 wherein A is selected from thc group consisting of phenylene, naphthalene, a bis-phenylene cc,mpound and mixtures thereof, which may be unsubstituted or ring substituted with a radical selected from the group consisting of halogen, hydroxy, C 1  to C 6  alkyl and C 1  to C 6  alkoxy. 3,3',4,4'-diphenyl tetracarboxylic acid dianhydride, 2,2-bis (3,4 dicarboxy phenyl) hexafluoropropane dianhydride, 1,2,4,5-benzene tetracarboxylic acid dianhydride, 4,4'-bis[2-(3,4-dicarboxyphenyl) hexafluoroisopropyl] diphenyl ether dianhydride, and mixtures thereof. 
     
     
       9. The polymers of claim 3 or 5 wherein said diamine is 4,4'-bis diphenylether. 
     
     
       10. A copolyimide of claim 4 comprising a mixture of aromatic dianhydrides. 
     
     
       11. A film comprising the polymer of claim 1 or claim 5. 
     
     
       12. The polymer of claim 5 prepared by forming the amide-acid condensation product of a 4,4'-bis diphenyl ether with one or more aromatic dianhydrides and imidizing said amide-acid condensation product. 
     
     
       13. The polymer of claim 5 wherein R is CF 3 .